Question: Who gave the {historic era} of {mountain system} of {Retezat Mountains} ?
Paraphrase: Who gave the {historic era} of {mountain system} of {Retezat Mountains} ?
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q389426 wdt:P4552 ?X . ?X wdt:P2348 ?answer}
Answer: Triassic